Measurements of upper atmosphere characteristics may include gas density, gas temperature, wind direction, and wind magnitude. Generally, there are two techniques used to make measurements or estimates for each of these parameters. The first technique is remote sensing that senses these parameters from a distance. The second technique is in-situ sensing that senses these parameters locally.
A variety of remote sensing methods currently exist. One class of methods registers signals from naturally existing airflow by use of sensitive optical components in space or on the ground. These methods integrate over a large volume of space, which suppresses detection of highly-structured atmospheric components. Another class of remote sensing methods is LIDAR-based sensing. LIDAR-based sensing utilizes active probing with an intense light source and performs a measurement of the signal returned by the atmosphere. These methods generally have been limited to altitudes below ˜150 km.
In situ techniques that make local measurements have also been used, and these methods generally detect gas directly on space-based platforms. Sensors based on pressure gauges or mass spectrometers have been used to make density measurements. Wind measurements have been made by sensors that modulate the flow of gas into the sensor by use of moving mechanical baffles, or using energy analysis of gas constituents after first ionizing those constituents within the instruments.
However, both of these techniques provide significant challenges for measurement of upper atmosphere characteristics. For example, with remote sensing, sensitivity is lost because measurement is performed over a large volume of space. With in-situ sensing, a more complex gas sensor is required and ionization of gas constituents is also required.
Thus, an alternative approach for measuring upper atmosphere gas characteristics may be beneficial.